getting closer but still some issues to iron out with these ultems... warning, a lot of words to follow. if you just want the cliff notes then here it is: ultem is a ..... to work with and I now know why no-one else makes an ultem mod, now if you want to avoid all the blah blah blah then just scroll down to all the pretty pictures
I know it's been taking me months to get these ultems up to the point of being able to produce them for you guys, and believe me it's not because it takes months to build them, it's because there are many obstacles to machining and producing a beautiful ultem product, and all these months have been from me developing solutions for each obstacle and trying to perfect each procedure to get the best finished product
it started with developing machining procedures and holding jigs for the different parts and writing the CNC code for each machining procedure, then another big obstacle was in being able to get the interior as clear and polished as the exterior for a clean clear transparent appearance.
I've gotten all of my machining processes down pat a while ago now, the first ultem mod I built looked great on the computer screen to you guys, but truth is that in person, to me, it kinda looked like crap. reason being that it was not optically clear, the insides were frosted and uneven, it was more translucent than transparent really, and up close you could see all of the internal machine and sanding marks... it didn't look bad but it certainly didn't look great either, not good enough for me to consider ready to sell as it was...
I mean yeah a lot of atty caps that are ultem are frosted or satin finish and I guess that looks ok for an atty cap when it's a very even finish, ideally an ultem component should be clear and polished or at the very least have an even frosted finish throughout, but because of all the interior orifices and tight corners in a complete mod like this it was just about impossible to polish the whole thing in and out completely or even get a uniform frosted finish including into all the corners and edges. I did a ton of research as to how this is achieved in industrial manufacturing and I seen that many ultem manufacturers mainly in the medical field use a procedure called vapor polishing, but they treat the actual procedure as a closely guarded trade secret so there are no real how-too's or much info about it out there, and there are no ultem vapor polishing machines available to buy for this really, so I did a lot of research and trial and error and developed and built my own vapor polishing machine
vapor polishing still requires a relatively nice finish before it is ready to polish, if you vapor polish over a bunch of machine and sanding marks then you'll just wind up with clear machine and sanding marks so the mods still require a lot of sanding and prep to get ready to polish, the media blaster was one of the last pieces of that puzzle...
ok so now I can machine it, finish sand it and now even polish it to a crystal clear glass like finish, so it should be ready to go now right? yeah? ha, I thought so too, until I actually tried to do so in this batch after finally setting up the media blaster to get an even sanded finish and now I discovered yet another problem, and what should be the last obstacle. the problem now is stress cracking, small internal stress cracks visible in the transparent ultem
the short version of the science behind this is that any time something is thermoformed as these ultem sheets are, it introduces internal stresses in the material, then cutting it and machining it also introduces more internal stresses, then sanding also adds more internal stress... well the vapor polishing procedure can cause stress cracks to appear when a part that is under these internal stresses is vapor polished...
I vapor polished the first torture test ultem mod after I finished building the vapor polishing rig and right away it showed up many of these internal stress cracks, but I just attributed that to the fact that I threw the mod around repeatedly and then ran it over with my truck, but now in vapor polishing the brand new batch of ultems I'm also getting some of these stress cracks showing up... mostly just in the doors because they wind up getting the most aggressive removal in material in the thinning operations, which means they wind up with the highest internal stresses. took me a while to figure out what the heck was even going on here and why on just the doors...
industrial manufacturers use a procedure to heat treat ultem while in production to eliminate chances of this very problem. heat treating the material is called annealing and this relieves the internal stresses to eliminate any stress cracks... to heat treat ultem requires slowly, over the course of several hours, bringing it up to 390 degrees, then holding it precisely there for a certain amount of time, then slowly bringing the temp back down, reducing by ~ 50 degrees per hour... this annealing procedure realigns the granular structure at a molecular level, relieving all of the internal stress, total time to anneal an ultem product winds up taking close to 24 hours and requires a precision programable air circulating scientific oven to effect this heat treatment. ideally it should be done before machining on the raw material to relieve stress in the material before even machining it, then again after machining to eliminate any new stresses created by machining
I do have some experience building PID programable ovens, I built a few for powder coating operations a while ago and I could build my own programable annealing oven for this, or I could just buy a commercial scientific oven, but I def have to do something cause I'm pretty sure no one is going to want an ultem mod with stress cracks all over the door and annealing it will result in a better finished product with no internal stresses that may cause an further cracking or crazing in use too...
this is of course only a problem on the amber ultem, the black ultem does not have this problem at all, these stress cracks themselves are more of a visual problem really, the material still has it's structural integrity, it's not like it's actually cracked all the way through or weakens it to the point that it's going to actually crack apart or anything, it's just more like little visible internal spider cracks but it of course looks like crap.
I'm extremely disappointed because I really thought I was over all the hurdles by now and I really thought I'd have amber and black ultem mods ready right now, but truth is, the amber is still not good enough just yet. I've already wasted a lot of ultem material in developing this mod and have a lot invested in this setup already too, but now I have to get this final annealing oven setup in place to anneal the ultem to stress relieve it so I can eliminate stress cracks from appearing when it's polished and relieve any stresses in the finished product so it's going to be just a little bit more time for amber ultem
here are a few shots of this batch so far... the amber bodied one with black door and chip cover is fine as well as all of the all black ones, but any one with an amber door is still just no good but at least there now a shiny ultra clear instead of a hazy frosted look
you can see some stress crack marks in the amber door on the black mod here
and here is more of what these stress cracks look like. luckily it's really only on the doors so I may be able to redo just the doors and then anneal the whole mod eliminating any future cracking or crazing issues
so all I have available right now today is all the full black ultems and the one amber with black door and chip cover, which is only half of this run. as far as black, I have 3 different finishes available, flat black, satin black and gloss black.
the flat black is a media blasted finish and has a slight roughness to it, personally not my thing but hey, someone might like it and it's available to those who do.
the satin black is a very nice look and my personal favorite, it has a very nice tactical feel in hand and has a very nice grip, not slippery at all, almost a rubbery type grip and feel
the gloss black is just like it sounds, ultra high gloss and smooth a glass. I could of course do combo's of these black finishes on one mod, IE; high gloss black body with satin face and door or vice versa or any kind of combo really. here is a few shots of the different back finishes available
left to right is gloss, satin and flat:
here is gloss VS flat
and gloss VS satin
I really can't afford to wait for the ambers to be done before releasing these black mods so if anyone on the list is waiting for black I may have to skip the amber people to sell some black then come back to the amber peeps, hopefully were talking another week or 2 here, I'm researching PID controllers and heat treating ovens right now and hope to have something in the works by next week, I really can't afford any more delays or setbacks here but then again I'm also really close now, this really should be the last obstacle here
